Software integrated development environments (IDEs) heretofore are not capable of integrating the functionality of an unmanaged hosted application into the development workspace. Thus, writing rich designers is normally a very complicated and time-consuming task that must consider very tight integration with the hosted applications.
What is needed is architecture that integrates the unmanaged application into the design environment in a coherent yet usable manner such that the developer can use the hosted application's native functionality yet leverage rich productivity features provided by the IDE.